JP2011047082A - Coated paper for printing and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coated paper for printing, free from printing unevenness, and having good operability and irregular texture appearance. <P>SOLUTION: The coated paper for printing includes at least an undercoating layer and a top coating layer on a base paper, wherein the undercoating layer contains ground calcium carbonate having an average particle diameter of ≥4 μm and ≤30 μm as a pigment in an amount of ≥40 pts.mass to 100 pts.mass of the total solid pigment component and a plate inorganic pigment having an aspect ratio (average particle diameter/thickness ratio) of 10-120 and an average particle diameter of ≥3 μm and ≤20 μm in an amount of ≥40 pts.mass to 100 pts.mass of the total solid pigment component, and the top coating layer formed on the undercoating layer contains a pigment composed solely of particles having an average particle diameter of ≤1.5 μm. There is further provided a method for producing the coated paper. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coated paper for printing having a texture with a feeling of unevenness, and more specifically, by controlling the type of pigment used for the undercoat coating layer and the method of providing the topcoat coating layer, The present invention relates to a coated paper for printing that can achieve both a texture of unevenness and a printing surface feeling that are not present.

  For coated paper for printing, attracting people's eyes is an important element as a product. Factors that attract the attention of the human eye include white paper properties such as the color of the coated paper for printing and white paper gloss, printability such as print gloss and printing unevenness, paper texture, and the like. Here, the texture of paper refers to a subtle unevenness on the paper surface and a natural feeling given by pulp fibers. In general, this texture and printability are contradictory physical properties, and in printing paper with a paper texture, the distribution of ink adhesion at each location on the paper surface changes due to subtle irregularities on the surface, resulting in a printed material with many unevennesses. . However, various papers have been developed to develop printing paper having high printability while having a texture due to surface irregularities.

  Examples of the device include a method of providing a coating layer on a base paper having a specified roughness (for example, see Patent Document 1), a method of using an organic pigment in the coating layer (for example, see Patent Document 2), and the like. .

  However, printing coated papers that have a texture with a feeling of unevenness depending on the unevenness of the base paper generally increase the texture of the feeling of unevenness as the coating amount on the base paper decreases. When the coating amount is small, uneven coating due to unevenness of the unevenness of the base paper or uneven internal structure in the coating layer occurs, and accordingly, uneven printing occurs.

  In addition, coating paper for printing, which uses an organic pigment in the coating layer and expresses a texture with a feeling of unevenness depending on the unevenness caused by the structure of the coating layer, the greater the blending amount of the organic pigment, However, at the same time, if the amount of the organic pigment is large, problems such as roll contamination at various locations during operation and paper blocking frequently occur.

  There is a method that uses an organic pigment whose glass transition temperature is controlled to achieve both a texture with a feeling of unevenness and operability (see, for example, Patent Document 3), but it is sufficiently effective for the problem of operability. The current situation is that the soiling of the roll is not completely eliminated. Further, when the paper is rolled up during operation, there is a problem that curling of the curl tends to occur.

Japanese Patent Laid-Open No. 11-12986 JP-A-7-166492 JP 2008-208474 A

  An object of the present invention is to provide a coated paper for printing having a texture with a feeling of unevenness, which has no printing unevenness and good operability.

  As a result of intensive studies to solve the above problems, the present inventors have invented the following coated paper for printing and a method for producing the same. That is, in a printing coated paper in which at least an undercoating layer and an overcoating layer are provided on a base paper, heavy calcium carbonate having an average particle diameter of 4 μm to 30 μm as a pigment is 40 parts by mass in 100 parts by mass of the total pigment solid content. In addition, an undercoat comprising a flat inorganic pigment having an aspect ratio (average particle diameter / thickness ratio) of 10 to 120 and an average particle diameter of 3 μm to 20 μm in 100 parts by weight of the total pigment solid content of 40 parts by weight or more. A coated paper for printing, characterized in that a coating layer is provided, and an overcoat coating layer composed only of particles having an average particle diameter of 1.5 μm or less is provided on the undercoat coating layer.

  Furthermore, it is preferable that the base paper has an arithmetic average roughness (Ra) defined by JIS B 0601 of 6.0 μm or more.

It is preferable to provide a solid content mass of 2.0 g / m ² or more and 10.0 g / m ² or less directly on the base paper as an undercoat coating layer. It is preferable to provide the top coat layer with a solid content of 2.0 g / m ² or more and 10.0 g / m ² or less per side.

  In the method for producing a coated paper for printing of the present invention, it is preferable that the top coat layer is provided by any one of an air knife coater, a curtain coater, and a spray coater. Further, it is more preferable to provide the undercoat coating layer directly on the base paper, dry the undercoat coating layer, and then provide the overcoat coating layer on the undercoat coating layer.

  The coated paper for printing according to the present invention has a feature that it has a texture with a feeling of unevenness, with no printing unevenness and good operability.

  Hereinafter, the coated paper for printing of the present invention will be described in detail. The printing coated paper of the present invention is one in which an undercoat coating layer is provided on a base paper, and an overcoat coating layer is provided thereon. Here, the topcoat coating layer is a layer corresponding to the outermost layer of the printing coated paper of the present invention, and the undercoat coating layer is located between the base paper and the topcoat coating layer, It is provided directly on the top. When providing a plurality of coating layers, an intermediate layer may be provided between the undercoat coating layer and the topcoat coating layer. As long as the operability and texture of the present invention are not affected, normal chemicals such as pigments and binders used for printing coated paper can be used for the intermediate layer.

<Undercoat coating layer>
In the coated paper for printing of the present invention, heavy calcium carbonate having an average particle size of 4 μm or more and 30 μm or less is used as a pigment in the undercoat coating layer, and the aspect ratio (average particle A ratio of diameter / thickness) is 10 to 120, and a flat inorganic pigment having an average particle diameter of 3 μm or more and 20 μm or less is contained in 40 parts by mass or more in 100 parts by mass of the total pigment solid content. The value of the average particle diameter in the present invention is measured using a MICROTRAC 3000II (trade name, manufactured by Nikkiso Co., Ltd., a laser particle size distribution meter) obtained by making a water-dispersed slurry under the optimum conditions so that the agglomeration of particles is most loosened. It is what. However, a kaolin clay is preferably a delaminated kaolin clay.

  By containing heavy calcium carbonate having an average particle size of 4 μm or more, a texture with an uneven feeling is generated on the surface of the undercoat coating layer. The heavy calcium carbonate having an average particle diameter of less than 4 μm has insufficient ruggedness. When the average particle diameter is larger than 30 μm, the unevenness is very good, but when the coating liquid is used to provide an undercoat coating layer, the precipitation of the pigment is remarkably fast and the water retention of the coating liquid is also poor. For this reason, there is a disadvantage that it is difficult to uniformly provide the coating layer on the base paper.

  In the undercoat coating layer of the present invention, in addition to heavy calcium carbonate, a flat inorganic pigment having an aspect ratio (average particle diameter / thickness ratio) of 10 to 120 and an average particle diameter of 3 μm to 20 μm (however, In the case of kaolin clay, delaminated kaolin clay) is used in combination of 40 parts by mass or more of 100 parts by mass of the total pigment solid content. The aspect ratio here is obtained by observing particles with an electron microscope (JSM-6390LA, manufactured by JEOL Ltd.) at a magnification of 10000 and measuring 10 arbitrary particles. When the coating amount of the undercoat coating layer is small, a texture with a feeling of unevenness is expressed. However, in this case, there is a disadvantage that the base paper is not sufficiently coated and printing unevenness is likely to occur. The flat inorganic pigment is excellent in covering the base paper and hardly causes printing unevenness, and thus is indispensable for achieving both a texture with a feeling of unevenness and printability. Moreover, when it is set as the coating liquid for providing an undercoat coating layer, the water retention of a coating liquid improves. Furthermore, the effect of suppressing curling of the curl was confirmed when the paper was rolled up during operation. When the aspect ratio is smaller than 10, neither the water retention improvement effect of the coating liquid nor the curl curl suppressing effect is sufficient. When the aspect ratio is larger than 120, when the coating liquid is used to provide an undercoat coating layer, the viscosity of the coating liquid increases excessively, which makes it difficult to provide a uniform coating layer on the base paper. . When the average particle size is less than 3 μm, it works to fill the voids between the heavy calcium carbonate particles used together, and the unevenness is reduced. When the average particle diameter is larger than 20 μm, when the coating liquid is used to provide an undercoat coating layer, the pigment settles quickly and the viscosity of the coating liquid becomes too high, so that the coating layer is provided uniformly on the base paper. The disadvantage is that it becomes difficult.

  When the tabular inorganic pigment having an aspect ratio (average particle diameter / thickness ratio) of 10 to 120 and an average particle diameter of 3 μm to 20 μm is kaolin clay, it is a delaminated kaolin clay. A delaminated kaolin clay obtained by simply peeling off a normal kaolin clay layered with hexagonal plates (delamination) is characterized by having the same thickness but a larger particle size compared to a normal one. . By using a delaminated kaolin clay, good base paper coverage is exhibited with a coating amount much smaller than that of other kaolin clays. In addition, ordinary kaolin is too small and enters the gaps between the bumps formed by heavy calcium carbonate particles, reducing the feeling of unevenness, but in the case of delaminated kaolin clay, there is no such feeling. It becomes possible to achieve both a certain texture and printability.

  The undercoat layer of the present invention has heavy calcium carbonate having an average particle size of 4 μm or more and 30 μm or less, an aspect ratio (average particle size / thickness ratio) of 10 to 120, and an average particle size of 3 μm or more and 20 μm or less. A flat inorganic pigment is used in combination. With heavy calcium carbonate alone, when the coating liquid is used to provide an undercoat coating layer, the water retention of the coating liquid is extremely poor, and a non-uniform coating layer that reflects uneven water absorption of the base paper is formed. This leads to uneven printing. In addition, the sedimentation rate of heavy calcium carbonate is too fast, causing clogging in the piping in the equipment for providing the coating layer, or in the case of a coater with a post-metering type coating method, When a shearing force is applied, troubles such as a large amount of solid matter in which calcium carbonate aggregates occur. In addition, when the flat inorganic pigment alone is used, when the finally obtained coated paper for printing is subjected to a smoothing treatment such as a calendar, it becomes too smooth and the texture with the unevenness is impaired.

  As the pigment used in the undercoat coating layer of the present invention, heavy calcium carbonate having an average particle diameter of 4 μm or more and 30 μm or less is 40 parts by mass or more in 100 parts by mass of the total pigment solids, and the aspect ratio (average particle diameter / thickness). As long as it contains 40 parts by mass or more of a flat inorganic pigment having an average particle diameter of 10 to 120 and an average particle size of 3 to 20 μm in 100 parts by mass of the total pigment solid content, the use of other pigments is not limited. Is not to be done. For example, heavy calcium carbonate other than the above, and a flat inorganic pigment other than the above (kaolin clay, mica, talc, plate barium sulfate, plate magnesium hydroxide, etc.) can be used in combination, and pigments other than these, Various light calcium carbonates, satin white, lithopone, titanium dioxide, alumina, aluminum hydroxide, zinc oxide, magnesium carbonate, natural silica, dry synthetic silica, wet synthetic silica, organic pigments, or those obtained by cation modification, or two of these More than one type of complex may be used in combination.

The undercoat coating layer of the present invention is characterized in that it is directly provided on a base paper with a solid content of 2.0 g / m ² or more and 10.0 g / m ² or less per side. In order to achieve both a texture with a feeling of unevenness and printability, it is necessary to provide an undercoat coating layer within this range. When the coating amount of the undercoat coating layer is small, a texture with a feeling of unevenness is manifested. However, when the solid content per side is less than 2.0 g / m ² , the coverage of the base paper is insufficient and printing unevenness occurs. Arise. When the solid content mass per one side exceeds 10.0 g / m ² , the texture with a feeling of unevenness is impaired. The method for providing the undercoat coating layer is not limited at all. Examples thereof include a blade coater, a rod coater, a curtain coater, an air knife coater, a spray coater, and various film transfer coaters such as a size press, a gate roll, and a shim sizer.

  The coating liquid for providing the undercoat coating layer of the present invention includes a binder in addition to the pigment, or a thickener, a dispersant, an antifoaming agent, a surfactant, a pH adjuster, and a water resistance agent as necessary. In addition, various commonly used auxiliaries such as colorants can be contained. As binders, various copolymer latexes such as styrene-butadiene latex, acrylic, polyvinyl acetate, ethylene-vinyl acetate, polyvinyl alcohol, modified polyvinyl alcohol, sodium polyacrylate, polyethylene oxide, polyacrylamide, urea, or melamine. And water-soluble synthetic compounds such as polyethyleneimine, polyamide polyamine, and epichlorohydrin. Furthermore, starch purified from natural plants, hydroxyethylated starch, oxidized starch, etherified starch, phosphate esterified starch, enzyme-modified starch and cold water soluble starch obtained by flash drying them, dextrin, mannan, chitosan, Examples thereof include natural polysaccharides such as arabinogalactan, glycogen, inulin, pectin, hyaluronic acid, carboxymethylcellulose, and hydroxyethylcellulose, oligomers thereof, and modified products thereof. Examples thereof include natural proteins such as casein, gelatin, soybean protein, and collagen, and modified products thereof, and synthetic polymers and oligomers such as polylactic acid and peptides. These can be used alone or in combination. The binder can be used after cation modification.

  The lower the binder content, the better the texture with unevenness, but the settling of the pigment in the coating liquid is slightly faster. On the contrary, when the binder content is large, there is no problem with the sedimentation of the pigment in the coating liquid, but compared to the case where the binder content is small, the texture with a slightly uneven feeling is inferior. Although it has such characteristics, if it is within the range of the above pigment composition and coating amount, regardless of the binder content, there is no unevenness in printing, the operability is good, and a texture with a feeling of unevenness. An undercoat coating layer is obtained because the coated coated paper for printing is provided.

<Topcoat coating layer>
The coated paper for printing according to the present invention is characterized in that an overcoat layer is provided on the undercoat coating layer with a solid content mass of 2.0 g / m ² or more and 10.0 g / m ² or less per side. As with the undercoat coating layer, a texture with a feeling of unevenness appears when the coating amount of the topcoat layer is small, but if the solid content on one side is less than 2.0 g / m ² , the printability is poor. Sufficient and uneven printing occurs. When the solid content mass per one side exceeds 10.0 g / m ² , the texture with a feeling of unevenness is impaired.

  The top coat layer of the present invention is characterized in that it is a single layer. If two or more coating layers are provided on the undercoat coating layer, the texture with a feeling of unevenness is impaired. Also, when the topcoat layer is not provided only with the undercoat coating layer, the large particle size pigment, particularly heavy calcium carbonate, that is present in the undercoat coating layer is directly exposed. In addition, since the pigment constituting the undercoat coating layer has a relatively wide particle size distribution, a smooth printing surface can be maintained while maintaining a texture with a feeling of unevenness by providing a single overcoat layer. Is provided.

  The pigment used for the top coat layer of the present invention is characterized by being composed only of particles having an average particle diameter of 1.5 μm or less. The present invention forms a texture with a feeling of unevenness by controlling the surface of the undercoat coating layer, and imparts printability without impairing the texture with a feeling of unevenness on the surface of the topcoat coating layer. When the topcoat coating layer is larger than the average particle size of 1.5 μm, a surface having unevenness that is more uneven than the surface of the undercoat coating layer is formed, resulting in printing unevenness.

  The coating liquid for providing the top coat layer of the present invention is a binder in addition to the above-mentioned pigment, or, if necessary, a thickener, a dispersant, an antifoaming agent, a surfactant, a pH adjuster, and water resistance. Various auxiliary agents usually used such as an agent and a coloring agent can be contained. The binder mentioned as an example of use is the same as that mentioned above as an example used for a coating liquid for providing an undercoat coating layer in the present invention.

  The present invention is characterized in that after the undercoat coating layer is dried, an overcoat coating layer is provided on the undercoat coating layer. The texture with the unevenness formed on the surface of the undercoat coating layer is manifested through a drying process. In a so-called WetOnWet coating method in which an undercoat coating layer is provided and a topcoat coating layer is provided immediately without passing through a drying step, a texture with a sufficient unevenness may not be exhibited. The degree of drying of the undercoat coating layer is not particularly limited.

  The top coat layer of the present invention is provided by any one of an air knife coater, a curtain coater (direct fountain coater), and a spray coater. Air knife coaters, curtain coaters, and spray coaters are more effective for contour coating than other methods, and by using these coating methods, the texture with unevenness formed on the surface of the undercoat coating layer is not impaired. It is possible to impart good printability. Examples of the coating method for providing the top coat layer of the present invention that are excluded from the target include a blade coater, a rod coater, and various film transfer coaters such as a size press, a gate roll, and a shim sizer.

<Base paper>
Examples of the base paper used in the present invention include chemical pulps such as LBKP and NBKP, mechanical pulps such as GP, PGW, RMP, TMP, CTMP, and CGP, and various wood pulps such as waste paper pulp, cotton, hemp, bamboo, and sugarcane. Plant fibers such as corn and kenaf, animal fibers such as wool and silk, cellulose regenerated fibers such as rayon, cupra and lyocell, semi-synthetic fibers such as acetate, polyamide fibers, polyester fibers, polyacrylonitrile fibers, polyvinyl alcohol For example, a chemical fiber such as a fiber, a polypropylene fiber, a polyvinylidene chloride fiber, or a polyurethane fiber, or an inorganic fiber such as a glass fiber, a metal fiber, or a carbon fiber in a sheet shape is used. However, those provided with a coating layer mainly composed of pigment on the surface are not included. These fibers include heavy calcium carbonate, light calcium carbonate, kaolin, talc, clay, titanium dioxide, aluminum hydroxide, silica, alumina, various fillers such as organic pigments, binders, sizing agents, fixing agents, and yields. Various compounding agents such as an agent and a paper strength enhancer can be suitably contained in accordance with each step and each material.

  In producing the base paper, a softening agent can be suitably contained in order to express a texture with a feeling of unevenness. The softening agent here is a compound having a hydrophobic group and a hydrophilic group, and is an oil-based nonionic surfactant, a sugar alcohol-based nonionic surfactant, a sugar-based nonionic surfactant, a polyhydric alcohol. Type nonionic surfactants, higher alcohols, higher alcohol ethylene and / or propylene oxide adducts, higher fatty acid ethylene oxide adducts, polyhydric alcohol and fatty acid ester compounds, fatty acid polyamidoamines, and the like.

  The base paper can be produced by using a general paper making process using a paper machine known in the paper industry such as a long paper machine, a twin wire paper machine, a combination paper machine, a round paper machine, a Yankee paper machine, a wet method, and a dry process. One or more are appropriately selected from each step such as a method, chemical bond, thermal bond, spun bond, spun lace, water jet, melt blow, needle punch, stitch blow, flash spinning, and tow opening. Paper can be made with any of acidic, neutral and alkaline.

  The base paper in the present invention may be subjected to a surface size press. As the components of the surface size press solution, starch purified from natural plants, hydroxyethylated starch, oxidized starch, etherified starch, phosphate esterified starch, enzyme-modified starch and cold water soluble starch obtained by flash drying them, Examples include acrylic surface sizing agents such as acrylic, styrene / acrylic, styrene / maleic acid, styrene / olefin, acrylic / vinyl acetate, and olefinic surface sizing agents such as olefin / maleic acid and diisobutylene / maleic acid.

  The surface roughness of the base paper in the present invention is not limited at all, and various surface treatments and calendar treatments may be performed as necessary. However, it is more preferable that the arithmetic average roughness (Ra) defined in JIS B 0601 of the base paper is 6.0 μm or more. When the arithmetic average roughness (Ra) defined in JIS B 0601 of the base paper is 6.0 μm or more, a coated paper for printing having a more textured texture is provided. In the present invention, the undercoat coating layer is designed to give a texture with a feeling of unevenness and the topcoat coating layer provides printability, but the arithmetic average roughness defined in JIS B 0601 of the base paper When the thickness (Ra) is 6.0 μm or more, an element of macroscopic undulation is added to the entire printing coated paper, and the texture of the unevenness is further increased.

<Finish>
The coated paper for printing in the present invention has sufficient printability even if it is not subjected to a calendar finishing treatment after the top coat layer is provided. If you do not perform the calendar finishing process, you can get a texture with a more uneven feeling, but if you do the calendar finishing process, the printability and curling curl curling effect when winding the paper in roll form Get higher. Of course, as long as it is within the scope of the present invention, regardless of the presence or absence of calendar finishing, the texture with unevenness, the printability, and the curl curl suppressing effect when winding the paper into a roll shape, both Fully express. When performing calendar finishing treatment, a device composed of a combination of hard rolls, elastic rolls, a pair of hard rolls and elastic rolls is preferably used as a machine calendar, soft nip calendar, super calendar, multi-stage calendar, It is called a nip calender or the like and may be heated intentionally. The temperature of the roll at the time of heating may reach a high temperature of about 250 ° C. from a medium low temperature of about 40 ° C. Also, an apparatus composed of a combination of a belt and a roll can be used, which is called a shoe calender, a metal belt calender, or the like.

  Examples of the present invention will be described below, but the present invention is not limited to these examples. Further, “parts” and “%” shown in the examples indicate parts by mass and mass% unless otherwise specified.

The physical properties of the coated paper for printing in each example and comparative example were evaluated by the following methods.
<Evaluation method>
1) Texture with a feeling of unevenness The texture with a feeling of unevenness was judged visually and evaluated by ◎, ○, Δ, and ×. However, in the present invention, “◎” and “◯” are the objects of the invention.
A: The unevenness on the surface of the coated paper for printing is large and the unevenness is uniformly present on the surface. O: The unevenness on the surface of the coated paper for printing has some unevenness, but the unevenness is large.
Δ: Unevenness on the surface of the coated paper for printing is small and insufficient.
X: The texture of unevenness is hardly felt on the surface of the coated paper for printing.

2) Printability The printability was evaluated by visually judging the printed surface of the obtained printed matter using a sheet-fed offset printing machine (DAIYA3H manufactured by Mitsubishi Heavy Industries, Ltd.) in the range of 1 to 5 points. However, in the present invention, 4 points and 5 points were the subject of the invention.
5 points: There was no portion that was not printed (white spots) on the surface of the coated paper for printing, and there was no printing unevenness.
4 points: There is some printing unevenness on the surface of the coated paper for printing, but no white spots are observed.
3 points: Printing unevenness is observed on the surface of the coated paper for printing, and white spots can be confirmed.
2 points: There are many white spots on the surface of the coated paper for printing, and the printed portion is uneven.
1 point: There are very many portions not printed on the surface of the coated paper for printing.

3) Operability Operability was actually produced as in each example by printing coated paper, judged visually, and evaluated in the range of 1 to 5 points. However, in the present invention, 4 points and 5 points were the subject of the invention.
5 points: No operational troubles such as roll stains at various locations, paper blocking, clogging of coating liquid, generation of agglomerated solids, etc.
4 points: Regarding the operational troubles listed above, only one item is slightly inferior, but there is no abnormality in the product quality, and the problem can be solved by a simple cleaning operation after production.
3 points: Regarding the operational troubles listed above, there are some inferior points in a plurality of items, there is no abnormality in the product quality, and the problem can be solved by a simple cleaning operation after production.
Two points: Regarding the operational troubles listed above, there is even one item that causes abnormalities in product quality.
1 point: Regarding operational troubles such as those mentioned above, there is one item that causes abnormalities in product quality, and the elimination of troubles after production also becomes a heavy burden.

<Base paper A>
A base paper for coating having a basis weight of 89.0 g / m ² was prepared with the following composition. A mass part here is the solid content mass ratio of each material with respect to 100 mass parts of total pulp solid content. After the paper making, the base paper was machine calendered so that the arithmetic average roughness (Ra) defined in JIS B 0601 was 6.12 μm.
<Base paper formulation>
ECF bleached LBKP (freeness 440 mlcsf) 85 parts by mass ECF bleached NBKP (freeness 490 mlcsf) 15 parts by mass
Light calcium carbonate (indicated by ash content in base paper) 6.0 parts by mass Commercial cationized starch 1.0 part by mass Commercially available cationic polyacrylamide yield improver 0.030 parts by mass Commercially available softener (polyester and fatty acid ester compound) 0.3 parts by mass

<Base paper B>
Paper was made in the same manner as the base paper A, and the base paper was machine calendered so that the arithmetic average roughness (Ra) specified in JIS B 0601 was 7.29 μm.

<Base paper C>
Paper was made in the same manner as the base paper A, and the base paper was machine calendered so that the arithmetic average roughness (Ra) specified in JIS B 0601 was 5.61 μm.

Example 1
A coating solution for providing an undercoat coating layer on the base paper was prepared as follows. A mass part here is a solid content mass ratio of each material with respect to 100 mass parts of total pigment solid content in a coating liquid. 50 mass parts of commercially available coarse-grained heavy calcium carbonate SFT-2000 (manufactured by Sankyo Seimitsu Co., Ltd., average particle diameter 25.4 μm), commercially available large particle size delaminated kaolin clay NUSURF (manufactured by BASF Corporation, average particle diameter 7) 0.5 μm of commercially available polyacrylic acid dispersant was added to 50 parts by mass of .6 μm, aspect ratio 93), and dispersed with a disperser at a solid content concentration of 62% by mass to obtain a pigment slurry. To this pigment slurry, 10 parts by mass of a commercially available styrene-butadiene copolymer latex as an adhesive, 2.0 parts by mass of commercially available phosphate esterified starch, and 0.50 parts by mass of commercially available calcium stearate are added, and sodium hydroxide is added. The pH was adjusted to 9.6, and the solid content concentration was adjusted to 52 mass% with adjusted water to obtain a coating solution for providing an undercoat coating layer. The coating liquid thus prepared was directly applied onto the base paper A using a blade coater with an operation speed of 200 m / min, a coating solid content mass of 6 g / m ² per side, and 12 g / m ^{2 on} both sides. Coating was performed under conditions, and after drying, an undercoat coated paper was obtained. The coating liquid for providing the topcoat coating layer was adjusted as follows. 0.10 parts by mass of a commercially available polyacrylic acid-based dispersant is added to 100 parts by mass of Hydra Gloss 90 of commercial high white primary kaolin (manufactured by Huber, average particle size 0.4 μm), and the solid content concentration is 70 by a disperser. A pigment slurry was obtained by dispersing at a mass%. To this pigment slurry, 13 parts by mass of a commercially available styrene-butadiene copolymer latex as an adhesive, 2.0 parts by mass of a 10% aqueous solution of commercially available polyvinyl alcohol (NM-11 manufactured by Nippon Gosei Kagaku Kogyo), and further commercially available calcium stearate are added. 0.70 part by mass was added, the pH was adjusted to 9.6 with sodium hydroxide, and the solid content concentration was adjusted to 48% by mass with adjusted water to obtain a coating solution for providing a top coat layer. The coating solution prepared in this manner was applied onto the above-mentioned undercoat coating layer using an air knife coater, an operation speed of 200 m / min, a coating solid content mass of 6 g / m ² per side, and 12 g / m on both sides. ^The coating was performed under the conditions of ² and dried to obtain a coated paper for printing. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Example 2)
In Example 1, commercially available coarse calcium carbonate SFT-2000 in a coating liquid for providing an undercoat coating layer on a base paper was used as a heavy calcium carbonate special grade of commercially available heavy calcium carbonate (manufactured by Sankyo Seimitsu Co., Ltd.). The same procedure as in Example 1 was conducted except that the average particle diameter was changed to 17.1 μm. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Example 3)
In Example 1, commercially available heavy calcium carbonate SFT-2000 in the coating liquid for providing an undercoat coating layer on the base paper was replaced with commercially available heavy calcium carbonate Escalon # 100S (Sankyo Seimitsu Co., Ltd., average The procedure was the same as in Example 1 except that the particle diameter was changed to 4.9 μm. The evaluation results of the obtained printing coated paper are shown in Table 1.

Example 4
In Example 1, NUSURF of commercially available large particle size delaminated kaolin clay in a coating liquid for providing an undercoat coating layer on a base paper was changed to BARRISURF (Imeris Minerals Co., Ltd.) of commercially available large particle size delaminated kaolin clay. The same procedure as in Example 1 was performed except that the average particle size was 8.2 μm and the aspect ratio was 100) manufactured by Japan. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Example 5)
In Example 1, NUSURF of commercially available large particle size delaminated kaolin clay in a coating liquid for providing an undercoat coating layer on a base paper was replaced with MK200 (commercially available from Coop Chemical Co., Ltd., average particle size) The same procedure as in Example 1 was performed except that 6.5 μm and the aspect ratio were 44). The evaluation results of the obtained printing coated paper are shown in Table 1.

(Example 6)
In Example 1, the commercial coarse-grained heavy calcium carbonate SFT-2000 in the coating liquid for providing an undercoat coating layer on the base paper was changed from 50 parts by mass to 45 parts by mass. NUSURF was changed from 50 parts by mass to 45 parts by mass, and commercially available light calcium carbonate TP-123 (Okutama Kogyo Co., Ltd., average particle size 0.6 μm) was changed to 10 parts by mass (dispersion conditions were not changed). Except for this, the same procedure as in Example 1 was performed. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Example 7)
In Example 1, Hydra Gloss 90 of commercially available high-grade white kaolin in a coating solution for providing a topcoat coating layer on an undercoat coating layer was mixed with FMT-97 (Fimatech Co., Ltd.), a commercially available heavy calcium carbonate. This was carried out in the same manner as in Example 1 except that the average particle size was changed to 0.8 μm. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Example 8)
In Example 1, it carried out similarly to Example 1 except having changed the coating system for providing a topcoat layer on an undercoat layer from an air knife coater to a curtain coater. The evaluation results of the obtained printing coated paper are shown in Table 1.

Example 9
In Example 1, it carried out similarly to Example 1 except having changed the coating system for providing a topcoat coating layer on an undercoat coating layer from the air knife coater to the spray coater. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Example 10)
The same procedure as in Example 1 was performed except that the base paper A was changed to the base paper B in Example 1. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Example 11)
The same procedure as in Example 1 was performed except that the base paper A was changed to the base paper C in Example 1. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 1)
In Example 1, commercially available heavy calcium carbonate SFT-2000 in a coating solution for providing an undercoat coating layer on a base paper was replaced with FMT-97 (manufactured by Pfematech Co., Ltd., average particle size) of commercially available heavy calcium carbonate. All operations were performed in the same manner as in Example 1 except that the diameter was changed to 0.8 μm. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 2)
In Example 1, from 50 parts by mass to 30 parts by mass of commercially available coarse-grained heavy calcium carbonate SFT-2000 in the coating liquid for providing an undercoat coating layer on the base paper, a commercially available large particle size delaminated kaolin clay The same procedure as in Example 1 was performed except that NUSURF was changed from 50 parts by mass to 70 parts by mass. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 3)
In Example 1, NUSURF of commercially available large particle size delaminated kaolin clay in a coating liquid for providing an undercoat coating layer on a base paper was replaced with hydra gloss 90 (manufactured by Huber, average particle) All operations were performed in the same manner as in Example 1 except that the diameter was changed to 0.4 μm and the aspect ratio was 4.4). The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 4)
In Example 1, from 50 parts by mass to 70 parts by mass of commercially available coarse-grained heavy calcium carbonate SFT-2000 in a coating liquid for providing an undercoat coating layer on a base paper, a commercially available large particle size delaminated kaolin clay The same procedure as in Example 1 was performed except that NUSURF was changed from 50 parts by mass to 30 parts by mass. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 5)
In Example 1, the coating amount of the undercoat coating layer provided directly on the base paper, coating solid mass 6 g / m 2 per ^surface, from 12 g / m ² on both sides, per surface coating solid mass 1 .8g / ^{m 2,} except that the 3.6 g / ^{m 2} on both sides was carried out in the same manner as in example 1. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 6)
In Example 1, the coating amount of the undercoat coating layer provided directly on the substrate paper, coating solid mass 6 g / m 2 per ^surface, from 12 g / m ² on both sides, the coating solids weight 15g per surface / ^{m 2,} except that the 30 g / ^{m 2} on both sides was carried out in the same manner as in example 1. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 7)
In Example 1, all steps were performed in the same manner as in Example 1 except that after the undercoating layer was provided on the base paper, the method was changed to a method in which the overcoating layer was immediately provided without passing through the drying step. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 8)
In Example 1, everything was carried out in the same manner as in Example 1 except that the coating method for providing the top coat layer on the undercoat layer was changed from an air knife coater to a blade coater. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 9)
In Example 1, everything was performed in the same manner as in Example 1 except that the coating method for providing the topcoat layer on the undercoat layer was changed from an air knife coater to a shim sizer. The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 10)
In Example 1, the coating amount of overcoat coating layer provided on the undercoat coating layer, the coating solids weight 6 g / m 2 per ^surface, from 12 g / m ² on both sides, coating solids per surface All operations were performed in the same manner as in Example 1 except that the mass was changed to 1.8 g / m ² and both sides were changed to 3.6 g / m ² . The evaluation results of the obtained printing coated paper are shown in Table 1.

(Comparative Example 11)
In Example 1, the coating amount of overcoat coating layer provided on the undercoat coating layer, the coating solids weight 6 g / m 2 per ^surface, from 12 g / m ² on both sides, coating solids per surface All were carried out in the same manner as in Example 1 except that the mass was changed to 12 g / m ² and 24 g / m ² on both sides. The evaluation results of the obtained printing coated paper are shown in Table 1.

  Table 1 shows the conditions and evaluation results of Examples 1 to 11 and Comparative Examples 1 to 11.

As apparent from the results in Table 1, heavy calcium carbonate having an average particle diameter of 4 μm or more and 30 μm or less as a pigment is 40 parts by weight or more in 100 parts by weight of the total pigment solids, and the aspect ratio (average particle diameter / thickness A flat inorganic pigment having a ratio of 10 to 120 and an average particle size of 3 μm to 20 μm (however, in the case of kaolin clay, it is delaminated kaolin clay) including 40 parts by mass or more in 100 parts by mass of the total pigment solid content After providing the coating layer characterized by this as an undercoat coating layer directly on the base paper with a solid content of 2.0 g / m ² or more and 10.0 g / m ² or less per side, and drying the undercoat coating layer On the undercoat coating layer, a topcoat coating layer in which the pigment is composed only of particles having an average particle size of 1.5 μm or less is obtained, the solid content mass per side is 2.0 g / m ² or more and 10.0 g / m ^2. Provided below, By providing the top coat layer with an air knife coater, curtain coater, or spray coater, there was provided printing paper with a texture with an uneven feeling that has no uneven printing and good operability. . Preferably, the base paper has an arithmetic average roughness (Ra) defined by JIS B 0601 of 6.0 μm or more, so that it has a texture with a more uneven feeling, no printing unevenness, and Coated paper for printing with good operability was provided.

Claims (6)

  In a printing coated paper in which at least an undercoating coating layer and an overcoating coating layer are provided on a base paper, 40 parts by mass of heavy calcium carbonate having an average particle diameter of 4 μm or more and 30 μm or less as a pigment in 100 parts by mass of the total pigment solid content In addition, an undercoat comprising a flat inorganic pigment having an aspect ratio (average particle diameter / thickness ratio) of 10 to 120 and an average particle diameter of 3 μm to 20 μm in 100 parts by weight of the total pigment solid content of 40 parts by weight or more. A coated paper for printing, characterized in that a coating layer is provided, and an overcoat coating layer composed only of particles having an average particle diameter of 1.5 μm or less is provided on the undercoat coating layer.   The coated paper for printing according to claim 1, wherein the base paper in claim 1 has an arithmetic average roughness (Ra) of 6.0 µm or more as defined in JIS B 0601. The coated paper for printing according to claim 1, wherein the solid coating weight per side is 2.0 g / m ² or more and 10.0 g / m ² or less directly on the base paper as an undercoat coating layer. The coated paper for printing according to claim 1, wherein the top coating layer is provided with a solid content of 2.0 g / m ² or more and 10.0 g / m ² or less per side.   The method for producing a coated paper for printing according to claim 1, wherein the top coat layer is provided by any one of an air knife coater, a curtain coater, and a spray coater.   6. The production of a coated paper for printing according to claim 5, wherein the undercoat coating layer is directly provided on the base paper, and after the undercoat coating layer is dried, the overcoat coating layer is provided on the undercoat coating layer. Method.